British Pat. No. 1,400,898, Storm and Nirschl, published July 23, 1975, discloses detergent compositions comprising, as a fabric-softening ingredient, a Smectite-type clay. Any Smectite-type clay having a cation exchange capacity of at least 50 meq/100 g is taught to be suitable.
It is now well recognized in the detergent industry that clays of the type disclosed in British Pat. No. 1,400,898 provide significant fabric softening benefits when used in a laundry detergent. It is equally well-recognized that the deposition of these clays onto the fabrics during the laundering process is far from complele; in fact, under typical European laundry conditions, less than half of the available clay is deposited onto the fabrics, the remainder being rinsed away with the laundry liquor during the rinsing cycles.
British Pat. Application No. 87-22844, Raemdonck and Busch, published Nov. 4, 1987, discloses granular and liquid detergent compositions containing a Smectite-type clay fabric softener and a polymeric clay-flocculating agent, from which the clay particles are more effectively deposited onto the fabrics during the laundering process. By enhancing clay deposition, more uniform fabric softening is produced and lower clay content in the detergent compositions can be used.
Product stability tends to be a problem with liquid clay-containing laundry detergent compositions. Generally, where such a composition contains both a clay and a flocculating agent (such as those described in British Application No. 87-22844), the flocculating agent tends to cause the clay to settle to the bottom of the product bottle.
In certain product environments, the clay itself may stabilize the detergent composition. For example, in typical claycontaining liquid laundry care compositions, many clays selfstabilize due to swelling in the high water-content environment. In low water content systems, however, another means must be employed to stabilize the clay.
It is well-known that organic compounds which contain a cation will react under favorable conditions by ion-exchange with clays which contain a negative layer-lattice and exchangeable cations to form organophillic organic-clay products. If the organic cation contains at least one alkyl group with 10 or more carbon atoms, then such organo-clays swell in certain organic liquids. See, for example, Finlayson, et al., U.S. Pat. No. 4,287,086; Hauser, U.S. Pat. No. 2,531,427; Jordon, U.S. Pat. No. 2,966,506; and the book "Clay Mineralogy", 2nd Edition, 1968 by Ralph E. Grim (McGraw-Hill Book Co., Inc.), particularly Chapter 10 (Clay-Mineral-Organic Reactions), pp. 356-368 (Ionic Reactions, Smectite), and pp. 392-401 (Organophillic Clay-Mineral Complexes), all incorporated herein by reference.
M-P-A.RTM. 14, an organically modified montonorillonite clay, manufactured by NL Industries, is described as an antisettling additive for solvent-based organic systems. (See NL Industries product description No. DS 154, 8/82). NL Industries also manufactures the BENTONE.RTM. family of rheological additives which exhibit similar organophillic properties.
Japanese Patent Application 62 [1987]-167216, Seiji Abe and Masayoshi Nakamura, published July 23, 1987, discloses a stable aqueous zeolite suspension which consists essentially of from 40% to 55% of a dehydrated zeolite with a particle size of from 0.1 to 10 .mu.m, and from 0.001% to 0.1% of a lipopolysaccharide biosurfactant. This aqueous zeolite suspension is described as being easier to handle for chemical processing unit operations.
It is an object of the present invention to provide a stable and aesthetically acceptable liquid fabric softener or heavy duty liquid detergent composition containing a Smectite-type clay in a low water/polyol content system.
It is also an object of the present invention to provide a stable and aesthetically acceptable liquid fabric softener, heavy duty liquid detergent or liquid delicate fabric detergent composition having a low water/polyol content, containing a fabric softening Smectite-type clay in combination with a clay-flocculating agent.
It is also an object of the present invention to describe a process for preparing stable clay-containing laundry detergent and fabric softener compositions, as well as a method for their use.